I'm migrating to W10, and installed Photoshop 21.0.3. It seemed to run more or less the same as on my W7 partition. So I updated to 21.1.... 😕 Immediately I noticed issues.
Firstly, Creative Cloud desktop has bloated out hideously, adding approximately double the processes and ram consumption. Lots of new features and functionality...but none I really need.
Secondly, 21.1 takes about 2x the time to load, often displaying this odd bordered black image under the splash screen. (see attached)
The next issue I noticed is that sliders (in the Levels, Hue & Saturation, Color Balance panels etc.) no longer live update and only apply the change in value after the mouse is released! I can't find any preference to return to previous slider behavior (including dynamic color sliders pref). This makes Photoshop basically unusable to me now...I'm far to ingrained in my workflow.
Another issue (that may only be the way Windows 10 thing) is that Photoshop consumes 1 gig more ram at idle than on W7, and it doesn't release that memory on shutdown.
I am going to revert to 21.0.3 and hope for the best....
[EDIT] Forgot to mention that the values sliders function normally on adjustment layers and in Camera Raw.